Injection device

ABSTRACT

An injection device that is used with a syringe, wherein the injection needle of the syringe is initially introduced into the skin and the injection fluid is injected afterwards. The injection device is essentially driven and controlled by a control sleeve ( 6 ) which can be displaced and/or rotated in relation to the housing ( 7 ) and which can be moved between a closing and functional position (P 1 ) and an open and safety position (P 2 ). In the closing and functional position, the control sleeve prevents access to the syringe and activates a release device for the injection process. In the open and safety position, a syringe ( 1 ) can be removed or inserted. A plurality of components carrying out the injection process (a slide ( 2 ) in which the syringe ( 1 ) is placed and a plunger ( 4 ) that impinges upon the syringe piston) are moved or controlled depending on the movement and position of the control sleeve or supported (for example, an ejection device for the syringe or a signaling device informing that injection has been completed). The device enables full-automatic injection that can be reliably carried out by patients themselves with few handling procedures.

CROSS REFERENCE TO RELATED APPLICATION

The present application is the national stage under 35 U.S.C. 371 ofPCT/DE99/01244, filed Apr. 24, 1999.

TECHNICAL FIELD OF THE INVENTION

The invention relates to an injection device with a syringe, inparticular a disposable syringe, for injecting an injection fluid underthe skin.

Carrying out medically appropriate injections by means of a syringepresupposes a minimum degree of medical knowledge and practical skill.Adherence to these requirements is usually guaranteed in the stationaryhospital or care sector, since, here, syringes are handled by medicallytrained specialized personnel; however, with the increase in chronicillnesses due to the increasing life expectancy of the population, thedomestic care sector is also increasing.

The result of this is that the handling of syringes must increasingly becapable of being carried out by the medical lay public as patients forthe purpose of self-treatment at home; apart from a certain threshold ofinhibition when a syringe is applied, adherence to the above-mentionedcriteria is also no longer guaranteed as the age of the patientincreases, for example because of motor disturbances or impaired vision.This has increasingly led, in recent decades, to the design of injectiondevices which operate partially or completely automatically and intowhich, in particular, conventional ready-made syringes can be inserted,so that it only remains for the patient to position the front end ofthis injection device on the place of injection and then actuate atrigger means in the injection device, in particular by finger pressure,whereupon the pricking of the needle and the injection of the injectionfluid are then carried out mostly under the effect of a spring means.Examples of such injection devices are shown in DE 29 50 140 C2, DE 1491 842 C2, DE 24 36 000 C2, EP 0, 144,625 B1, EP 0, 516,473 B1 and EP 0,577,448 A1.

PRIOR ART

The invention proceeds from a generic device, such as is described by FR2 733 155 A. This injection device contains built-in parts which areheld in the housing and which, under the action of a spring as drivemeans, load the syringe in such a way that, as a result of a successivelinear displacement of the syringe and of the injection needle in thehousing, first the introduction of the injection needle of the syringeunder the skin takes place and only thereafter is the injection fluidinjected. After injection has taken place, these structural parts arethen returned to their initial position again as a result of an oppositemovement. Within this cycle of movement, it is necessary to extract theemptied disposable syringe from the injection device and replace it by afilled, new disposable syringe, so that the injection operation can thenbe restarted anew.

To that end, the housing has an axially displaceable control sleeve,which after the return of the built-in parts that effect the lineardisplacement is drawn into an opening position, whereupon a newdisposable syringe can be put in place and the control sleeve can bethrust into a closing and operating position. The tension of the springthat effects the injection stroke is generated here upon retraction ofthe control sleeve, until a locking position is reached, to which endthe spring force to be overcome must be fully brought to bear by thepatient to its full extent as a tensile or compressive force. Theexecution of one complete injection cycle in this design requires aplurality of a successive handling actions in a fixed order.

U.S. Pat. No. 5,137,516 A shows an actuation unit and a housing unit forreceiving the syringe, which for actuating the syringe must be placedagainst one another in axially aligned fashion and joined together. Tothat end, a screw sleeve is provided which is a component of the housingunit, and onto which the actuation unit can be screwed once a filledsyringe has been put in place, and from which the actuation unit has tobe unscrewed again after the injection has been made, so that the emptysyringe can be removed.

German Utility Model DE 89 12 091 U shows an injection device operatingin a single stage, in which the piercing of the skin and the injectionproceed simultaneously. As in the aforementioned U.S. Pat. No.5,137,516, an actuation unit and a housing unit for receiving thesyringe are provided, but they are disposed fixedly parallel to oneanother and thus form a structural unit. A “column” is axially guided inthe actuating unit and has a plate on its upper end that by rotation ofthe column either blocks or releases the insertion opening of thehousing unit, thus defining a closing and operating position and anopening position relative to the housing unit.

The handling of both these last two injection devices when thedisposable syringe is being changed requires, particularly when the twohousing parts, together with the reinserted, new ready-made syringe, arebrought together accurately in terms of fit and direction, some degreeof manual skill which cannot be presupposed in the group, referred toabove, of chronically sick, older people; this previously known solutionis therefore somewhat unsuitable for this group in particular.

SUBJECT OF THE INVENTION

The essential object of the invention is to develop generic injectiondevices in such a way that, whilst having a simple mechanical design,the patient's actions required for handling are reduced to a minimum, inparticular the extraction and insertion of the disposable syringe aresimplified to such an extent that only minimal requirements are demandedof the (remaining) physical and mental abilities of the patient.

This object is achieved, according to the invention, in conformity withthe defining part of patent claim 1.

The essential idea of the solution according to the invention is tocombine a multiplicity of drive, control and safety functions in acentral structural part, the control sleeve, which manually is extremelyeasy to handle, since it needs merely to be rotated relative to thehousing:

The control sleeve is part of the housing inasmuch as it serves, insteadof, for example, a flap, for closing and for opening the interior of thehousing, in which the ready-made syringe is held.

The control sleeve is part of the drive means insofar as, when thehousing is being opened by the rotation of the control sleeve, acounterstroke of the slide and tappet is generated counter to the actionof a spring executing the injection strokes, said counterstrokeconveying these two structural parts into their original lockingposition again, separate measures and actions not being required forthis absolutely necessary sequence.

The control sleeve is also a control means insofar as, depending on itsposition, it blocks the trigger means of the injection device or permitsits activation.

The control sleeve also makes it possible to have further advantageousembodiments of the solution according to the invention for increasingthe operating safety and handling convenience, insofar as it directlyactuates an ejection means which, after injection has taken place,automatically presses the empty ready-made syringe toward the patient,when the housing is opened, by means of the control sleeve, and thusmakes extraction easier, and said control sleeve is also utilized forfeedback of the position and operating state of the injection device,said feedback being capable of being easily detected by the patient'ssenses.

Other advantageous embodiments according to the invention relate to aclearly detectable, acoustic signal means, by which the end of aninjection operation is indicated to the patient.

This diversity of functions can be implemented by means of a simpledesign of the injection device; thus, the essential structural parts ofthe injection device can, for example, take the form of injectionmoldings which can easily be mounted, so that the injection device canbe produced cost-effectively in terms of material and labor.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred exemplary embodiments of the injection device according to theinvention are now explained in more detail by means of the drawings inwhich:

FIG. 1 shows a first longitudinal section through the injection devicein its opening position for the insertion or extraction of the syringe,in the plane I—I of FIG. 3,

FIG. 2 shows a first cross section through the injection device in itsopening position, in the sectional plane A—A of FIG. 1,

FIG. 3 shows a second longitudinal section through the injection devicein its opening position, in the sectional plane III—III of FIG. 1,

FIG. 4 shows a first side view of the signal means of the injectiondevice, in the sectional plane of FIG. 1,

FIG. 5 shows a second side view of the signal means of the injectiondevice, in the sectional plane of FIG. 3,

FIG. 6 shows a third longitudinal section through the injection devicedirectly at the start of the second stroke, in the plane of FIG. 1,

FIG. 7 shows a fourth longitudinal section through the injection deviceduring the second stroke, in the plane of FIG. 1,

FIG. 8 shows a fifth longitudinal section through the injection deviceat the end of the second stroke, in the plane of FIG. 1,

FIG. 9 shows a second cross section through the injection device at theend of the second stroke, in the plane B—B of FIG. 8,

FIG. 10 shows a sixth longitudinal section through the injection deviceat the end of the second stroke, in the plane X—X of FIG. 8,

FIG. 11 shows a perspective view of the casing MI of the control sleevewith a control cam,

FIG. 12 is a developed view of the inner casing surface MI of FIG. 11with one control cam,

FIG. 13 is a developed view of the inner casing surface of the controlsleeve in a variant having two control cams,

FIGS. 14A, B are sections taken in the planes C—C and D—D through thecasing part of the control sleeve of FIG. 13,

FIGS. 15A, B, C shows sections and perspective views of the ejectionmeans,

FIGS. 16A, B, C, D shows perspective views of one exemplary embodimentof the slide with an integrated gear,

FIGS. 17A, B, C shows views and a longitudinal section through the gearside of FIG. 16,

FIG. 18 shows the injection device with the built-in gear slide, and

FIG. 19 is a horizontal fragmentary section through the injection devicein the region of the gear slide.

DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENT

The basic design of the injection device according to the invention willbe explained first, followed by the individual operating segments withina work cycle.

The injection device possesses, as it were as a “mechanical supportingskeleton”, a housing 7, the front portion 7C of which tapers conicallywhere the needle 13 of the syringe 1 emerges, said housing beingdesigned essentially cylindrically in its middle portion 7B and merginginto a rear, caplike handling portion 7A with a housing rear wall 74having an annular groove 75. The longitudinal axis F of this housing 7forms the longitudinal axis, that is to say that axis 30 in which thesyringe 1 is held and in which the essential movements and controloperations for injection also consequently take place.

The housing 7 has, in its middle portion 7B adjoining the front portion7C, a loading orifice L7 which extends over an acute circumferentialangle with respect to the longitudinal axis F, in the exemplaryembodiment illustrated, the middle part of the housing 7 extending overan angle α2 of about 270°, so that the loading orifice L7 of the housing7 occupies approximately a circumferential range of 90°. The interior ofthe housing 7 is accessible via this loading orifice L7 for theinsertion and extraction of a syringe 1.

In order to make the basic design of the housing 7 clear, the latter isillustrated by close hatching in FIG. 3.

Held on and in this housing 7 is a control sleeve 6 which is astructural operating part particularly essential to the invention andwhich is rotatable coaxially to the housing 7 about the longitudinalaxis, of the latter, as illustrated, in particular, in FIGS. 2 and 9.The control sleeve 6 has, initially, a front, tapered guide portion 6Cwhich is seated essentially positively on the forward-tapering frontportion 7C of the housing 7 and which is held rotatably on this portionof the housing 7. Said guide portion has adjoining it an essentiallycylindrical middle portion 6B which, over part of its circumference, hasa loading orifice L6 for the insertion and extraction of the syringe 1from the housing 7. This middle region extends over an angle α1 oflikewise about 270° correspondingly to the housing 7, so that an orificeangle of likewise about 90° remains for the loading orifice L6.

In a first function, essential to the invention, of this design of thecontrol sleeve 6 and housing 7, the control sleeve 6 slides on thecasing surface M of the housing 7 as a result of the rotation of thecontrol sleeve 6 on the latter, so that, in an opening and securingposition P2 (FIG. 2), the two loading orifices L6 of the control sleeve6, on the one hand, and L7 of the housing 7, on the other hand, areessentially congruent, that is to say, in this opening and securingposition P2, the control sleeve 6 opens the loading orifice L7 of thehousing, so that the user has access to the syringe 1 held in thelongitudinal axis F.

As a result of the rotation of the control sleeve 6 on the casingsurface M (symbolized by the double arrow in FIG. 9), a position can beproduced, in which the control sleeve 6 completely closes the loadingorifice L7 of the housing 7 (FIG. 9) and thus defines a closing andoperating position P1 of the injection device according to theinvention.

This “changeover function” of the control sleeve 6 between the closingand operating position P1 and the opening and securing position P2 isone of the essential functions of the control sleeve.

Another important task, specifically the drive and control function forthe multiplicity of structural operating parts which are arranged in thehousing and which are also explained further below, is the cooperationof the rear, cylindrical control portion 6A of the control sleeve 6having an annular groove 75 of the housing 7. The inner casing surfaceMI of the cylindrical control portion 6A of the control sleeve 6 isprovided with profiles or profile tracks which are designed as controlcams 64, 65, 66 and 67, as is illustrated in the developed view of theinner casing surface MI of FIGS. 11 and 12. These control cams cooperatewith control elements of further structural parts which are held withinthe housing 7 and serve for generating two injection strokes and thedesign of which is described below:

The middle portion 7B of the housing 7 (outer casing surface M) is ofhollow-cylindrical design, that is to say it also has an inner casingsurface N (FIG. 2). In the interior thereby produced in the middleportion 7B slides a partially cylindrically designed slide 2. This slide2 has a rear first portion 2A, which is designed as a hollow cylinder,and a front approximately semicylindrical second portion 2B which islikewise guided in the housing 7 and which has a groove-shaped orslitlike retention 21 for positioning the syringe collar 12 of thesyringe 1, so that the syringe 1 is thereby fixedly positioned and heldin the slide 2 in the direction of the longitudinal axis F, that is tosay, in particular, the axial position of the injection needle 13 of thesyringe 1 in the longitudinal axis F is unequivocally determined by theposition of the syringe collar 12 and, consequently, the axial positionof the slide 2 in the housing 7.

The axial movement of the slide 2 in the longitudinal axis F is limitedbetween a locking position Al and an advanced position V1 by suitableabutting and securing means within the housing 7, that is to say, in theadvanced position V1, the syringe 1 is located with its injection needle13 in the position extended out of the tip of the housing 7 andfunctionally ready for injection, and, in the locking position A1, theslide is located in its rear position, in which the injection needle 13is retracted within the outlet duct 7D in the front portion 7C of thehousing 7.

This axial movement of the slide 2 between the locking position A1 andthe advanced position V1 is designated below as the “first stroke” H1(stroke I in FIG. 1). This stroke thus serves for moving the syringe 1forward as an entire operating unit, that is to say for pricking theneedle 13 to the medically required depth of tissue under the skin whenthe outlet orifice of the duct 7D sits on the skin.

A tappet 4 designed in the manner of a ram is centrally mounted axiallydisplaceably in the first portion 2A of the slide 2. This tappet 4 isdesigned, at its end pointing toward the handling portion 7A of thehousing 7, as a guide portion 4A which has the same outside diameter asthe first portion 2A of the slide 2, so that these two structural partsare axially displaceable in the middle portion 7B of the housing 7.

That end face of the tappet 4 which points toward the front end of theinjection device is located directly opposite the end face of thesyringe plunger 14, so that an axial displacement of the tappet 4 in theslide 2 (in which the syringe 1 is held fixedly) leads to loading of thesyringe plunger 14 and, consequently, to the pushing of the syringeplunger 14 into the syringe 1 and to the emission of the injection fluidthrough the injection needle 13. The tappet 4, too, is thus axiallydisplaceable between two positions, specifically between a lockingposition A2 (for example, FIG. 6), in which there is no contact with thesyringe plunger 14, and an advanced position V2 (for example, FIG. 8),in which the syringe plunger 20 14 is pushed completely into the syringe1, insofar as there is provision for this, and the injection fluid hasbeen injected in the desired quantity into the tissue via the injectionneedle 13.

The movement of the tappet 4 between the locking position A2 and theadvanced position V2 is designated below as the “second stroke” H2(stroke II in FIG. 1).

It should be made clear, once again, that the first stroke H1 of theslide 2 leads to the axial advance of the entire syringe 1 and thereforeof the injection needle 13 and, consequently, to the pricking of theinjection needle 13, whereas only the second stroke H2, the axialmovement of the tappet 9, then leads to loading of the syringe plunger14 and to the injection of the injection fluid through the (pricked)injection needle 13.

Another essential feature of the solution according to the invention,then, is the control-related implementation of these successive firstand second strokes H1, H2 for carrying out a complete pricking andinjection sequence:

This purpose is served by a pinlike coupling element 8 which is locatedbetween the slide 2 and the tappet 4 and which, during the first strokeH1 of the slide 2,10 couples the latter and the tappet 4 to one anothervia a first catch element 81 in the tappet 4 and, after the expiry ofthe first stroke H1, releases the coupling by means of a second catchelement 73 in the housing 7, so that the tappet 4 alone can then carryout the second stroke H2.

In the exemplary embodiment illustrated, the coupling element 8 consistsof a bolt like pin with conically shaped end faces. In a mannercorresponding to this shape of the end faces, the two catch elementsconsist of depressions 72 and 81 in the tappet 4 and in the housing 7respectively, said depressions being essentially complementary to theseend faces, and, in particular, the corresponding conical slopes in thesedepressions are important.

In the locking position A2 of the tappet 4, the latter is connected tothe slide 2 via the coupling element 8, in that the inward-pointing endface of the latter engages into the depression 81 of the tappet 4,whereas there is no depression on the inner casing surface of theopposite portion of the inner casing of the housing 7. Consequently, thetappet 4 and slide 2 are positively coupled in their movement andconsequently jointly execute the first stroke which leads to thepricking of the injection needle 13.

The advanced position V1 of the slide 2 is defined correspondingly bythe positioning of the depression 72 in the housing 7: as soon as theslide 2 has reached the selected advanced position in the housing 7, thecoupling element 8 reaches the depression 72 and, as a result of theconical shape, slides with its end face confronting said depression intothe latter, with the result that its opposite end face is freed from thecorresponding depression 81 in the tappet 4, the consequence of thisbeing that the positive coupling between the tappet 4 and slide 2 iscanceled. Further loading of the tappet 4 in the direction of thesyringe 1 then leads, therefore, to the execution of the second strokeH2 for injecting the injection fluid, until the front end face of theguide portion 4A of the tappet 4 rests on the rear end face of the firstportion 2A of the slide, thereby defining the advanced position V2 ofthe tappet 4 (FIGS. 8 and 10).

So that these two strokes H1 and H2 can be carried out in the orderdescribed, jointly by the slide and the tappet (stroke 1) and by thetappet alone (stroke 2), a drive means is required, which loads thetappet 4 on its end face pointing towards the housing rear wall 74; forthis purpose, in the exemplary embodiment illustrated, a helical spring3 is provided, which is arranged coaxially to the operational axis F andof which one end is supported on the tappet 4 and the other end isseated on a holding block 31 which, in turn, is held in the housing rearwall 74.

The spring force of this helical spring 3 is dimensioned in such a waythat it is sufficient for carrying out the two strokes H1 and H2, thatis to say, in particular, up to the complete injection of the injectionfluid.

The helical spring 3 is consequently in its tensioned state when theslide 2 and tappet 4 are in their respective locking position A1 and A2.

Between the positions of the tappet 4 and slide 2, on the one hand, andthe positions P1 and P2 of the control sleeve 6, on the other hand, acoupling is defined, in that further structural operating parts areprovided, which ensure that the slide 2 and tappet 4 must necessarily bein their respective locking position A1, A2 when the control sleeve 6 isin its opening position P2, or, conversely, that only when the controlsleeve 6 has assumed its closing and operating position P1 (when theloading orifice L6 closes the loading orifice L7) can the tappet 4 andslide 2 leave their respective locking positions and assume theiradvanced positions V1 and V2 defined above, being moved by the force ofthe helical spring 3.

There is provision, furthermore, after injection has been carried out,that is to say when the control sleeve 6 is rotated again from itsclosing and operating position P1 into its opening and securing positionP2, for this rotational movement to ensure, via the profilings, referredto initially, on the casing inside MI, a corresponding return of thetappet 4 and slide 2 into their respective locking positions A1 and A2,in other words access into the housing 7 through the loading orificesL6, L7 can take place only when it is ensured that the tappet 4 andslide 2 are located again in their respective locking positions, inwhich, of course, the spring 3 is then tensioned again and is ready fora new injection stroke.

The design-related implementation of this control principle, then, isexplained in detail in two exemplary embodiments:

A preferred implementation of the control-related coupling between thecontrol sleeve 6 and the slide 4 is shown in FIGS. 11 and 12; in thisimplementation, two structurally identical lifting bolts 42 and 43 areprovided, which with profiling in the form of a sawtoothlike control camcooperate with the control cam portions 68, 69 on the inside MI of thecasing of the control sleeve 6. This is a structurally simple version,in which the affects of friction between the lifting bolts 42, 4 and thecasing inside MI are merely minimal; because of the perpendiculartrailing edges of the portions 68, 69 of the control cam, an unambiguousfunctional association with the direction of rotation DR exists.Reducing frictional factors leads to a low actuating torque and thusmakes for easy manipulation.

An alternative implementation of the control-related coupling betweenthe control sleeve 6 and the slide 4 is shown in FIGS. 13 and 14, inwhich the same reference numerals are also used for identical parts.

In both implementations of this coupling, the coupling is attained vialifting bolts 42 and 43 of the same or different diameter, which areretained crosswise to the longitudinal axis F in the rear portion 4A ofthe tappet 4, and which are dimensioned and oriented in the tappet 4 insuch a way that a nonpositive engagement is attained between the liftingbolts 42, 43 on the one hand and the control cam portions 64-67 (FIGS.13 and 14) or 68, 69 (FIGS. 11 and 12) on the other. It is thuspossible, by rotating the control sleeve 6, to convert the torqueexerted here via the various control cams into a linear restoring forceof the tappet 4 counter to the tensing force of the spiral spring 3, sothat the tappet 4 and the slide 2 are pushed back in the housing 7 farenough that they regain their respective locking positions A1 and A2.The total counterstroke ΔH executed corresponds in its value to the sumof the two strokes H1 and H2 of the tappet 4 and slide 2. The form ofthe two control cams shown in the developed view of the inside casingsurface MI in FIG. 13 is due to the fact that the implementation of thetorque upon rotation of the control sleeve 6 is to be done with the mostconstant possible torque over the entire counterstroke ΔH, to make theinjection device easier to manipulate. Because of the opposeddisposition of the two lifting bolts 42, 43, the counterstroke ΔHgenerated by the control sleeve 6 is transmitted to the tappet or slidein such a way that tilting moments on the tappet and/or slide that couldcause canting or seizing are reliably precluded. The distribution of thetorque transmission to the two lifting bolts 42, 43 makes a short guidepath of the tappet 4 possible and thus a tight, compact design of theinjection device in this region.

The design of the control cam portions 64-67 and 68-69 is preferablyselected such that the control sleeve 6 can be unmolded from aninjection molding tool without difficulty.

Since in the exemplary embodiment of FIGS. 13 and 14 the diameter of thefirst lifting bolt 42 is significantly less than the diameter of thesecond lifting bolt 43, the associated control cam portions 64 and 65 donot intersect at an angle of 90° but rather somewhat earlier. Thisoffset of the point of intersection has the result that the lifting bolt42 which in this exemplary embodiment is spring-loaded executes an axialmotion in response to the force acting on it from the spring 44, andalready leaves the control cam portion 64 in position 42 a and slides onthe adjoining control cam portion 67. In this position of the controlsleeve 6, the also spring-loaded (spring 45) lifting bolt 43 is stilllocated on the control cam portion 65. This assures that only onelifting bolt at a time will ever be in transition from one control camportion to the next, so that an assured force transmission from thecontrol sleeve 6 to the tappet 4 always takes place via at least one ofthe two lifting bolts 42, 43.

Below the positions 42 d and 43 d shown in FIG. 13, the control camportions 66, 67 are provided with slide ramps 61, 62, by way of whichthe lifting bolts 42, 43 return to their outset position (parallelarrows S in FIG. 13).

A further design-related implementation of the control principle bymeans of the control sleeve 6 relates to securing the injection devicein the locking position of the tappet 4, depending on the angularposition of the control sleeve 6:

For this purpose, two mutually opposite securing pawls 41 are integrallyformed as securing means on the rearside of the guide portion 4A of thetappet 4 and, when the control sleeve 6 is in the opening and securingposition P2, said securing pawls are in releasable engagement with twocontrol pawls 53 and 54, displaceable transversely to the operatingdirection F, of a trigger means and thus hold the tappet 4 in itslocking position A2 counter to the pretension of the helical spring 3.In the exemplary embodiment 5 illustrated, the engagement described issuch that the two securing pawls 41 have noses which point in the samedirection and which slide over the rear surfaces of the control pawls53,54 into the locking position, for which purpose the control pawlshave ramp like slopes, so that engagement causes the securing pawls 41to snap in elastically over the control pawls 53, 54, as illustrated inFIG. 1.

The control pawls 53 and 54 are part of a trigger means which is ledoutward through the housing 7 in the handling portion 7A of the latterand is designed as an actuating button 5. This actuating button 5,together with the control pawls 53 and 54, can be moved in the housing 7counter to a spring 51 which ensures that securing engagement,illustrated in FIG. 1, between the tappet 4 and trigger means ismaintained.

Cooperation between the actuating button 5 and control sleeve 6, then,is such that the actuating button 5 can be displaced (and consequentlythe securing pawls 41 released) only transversely to the operationalaxis F, when the control sleeve 6 is in its closing and operatingposition P1. Since this closing and operating position P1 is definedunequivocally by the angular position of the control sleeve 6 on thehousing 7 (cf. FIG. 2), this control coupling between the actuatingbutton 5 and control sleeve 6 is achieved in a simple way, in that therear edge region of the control portion 6A of the control sleeve 6extends at the rear 35 over a nose 5A of the actuating button 5 (engagesbehind said nose) and, only in the corresponding angular sector whichcorresponds to the closing and operating position P1, has an edge recess6A1 (FIG. 11), through which the nose 5A of the actuating button 5 canpass in the closing and operating position P1. Consequently, when thecontrol sleeve 6 is in the operating and closing [sic] position P1, thelocking position A2 of the tappet 4 can be canceled, in that theactuating button S is pressed into the housing 7 and, consequently, thecontrol pawls 53, 54 release the two securing pawls 41, with the resultthat the helical spring 3 can then immediately exercise its force andthe two strokes H1 and H2 are executed in succession, as describedinitially.

For the unequivocal definition of the two positions P1 and P2 of thecontrol sleeve 6, there is provision, furthermore, for the frontconically tapering guide portion 6C of the control sleeve 6 to havemutually opposite, inwardly directed, dish-shaped recesses 77A and 77Bwhich are in interaction with a spring-loaded catch element 77 held inthe housing 7. When the control sleeve 6 is in the opening and securingposition P2 illustrated in FIG. 1, the catch element 77 is in engagementwith the recess 77A, and, in the closing and operating position P1illustrated, for example, in FIG. 8, the catch element 77 is thereforein engagement with the depression 77B.

The brief, active rotation of the control sleeve 6 brought about by thiscatch mechanism thus ensures that the two basic positions P1 and P2 ofthe control sleeve 6 are detected by the user's senses and consequentlyalso serves, as it were, as a feedback of the current operating state ofthe injection device, thus further increasing the operating safety.

Proper, reliable functioning of the injection device is already possibleby means of the structural operating parts described above, but, forfurther refinement and improvement, other means are also provided whichare additionally presented briefly below:

A rotation damper 100 of a commercially available type, which isconnected to the housing 7 via a rack 101, is provided in the slide 2.This is a rotation damper, such as is obtainable, for example, under theproduct designation FRT-C2 from the company ACE Sto8dampfer GmbH ofD-40764 Langenfeld. Such a rotation damper 100 operates essentially bythe interposition of a means of specific viscosity in the relativemovement between the body and the rack 101, so that a force actingbetween these two components causes lower acceleration during theresulting linear displacement. In the injection device, the functioningof the rotation damper 100 is selected in such a way that theacceleration of the slide 2 during the first stroke H1 (that is to say,with the high tension force of the spring 3) is limited to a desiredvalue which, on the one hand, still ensures reliable, rapid pricking ofthe injection needle 13 into the tissue, but, on the other hand, avoidsoverly apparent abutting effects, such as jolts and vibrations at theend of the first stroke H1, so that generally “smoother” operation isachieved during injection.

In order to make handling easier when the syringe 1 is extracted afterthe injection operation has ended, an ejection means is providedopposite the loading orifices L6, L7 of the housing 7 and of the controlsleeve 6 (that is to say, to that extent “below” the syringe 1), saidejection means being activated during the opening of the injectiondevice (rotation of the control sleeve 6 from the closing and operatingposition P1 into its opening and securing position P2), to the effectthat said ejection means lifts the rear end of the syringe 1, as itwere, toward the user and makes extraction easier. Here, too, thefunction of the control sleeve 6 as a control means should be emphasizedagain, in that specific functions or additional functions are activatedor made possible solely as a result of the actuation of the controlsleeve.

The ejection means (see, in particular, FIG. 15 in this respect)contains, initially, an ejection lever 200, one leg end of which is heldpivotably on the slide 2 by means of a pin 201, in such a way that itsother leg end angled at 90° can be moved in the direction of the syringe1. For this purpose, the slide 2 has a corresponding recess or slope 2Cwhich at the same time also defines the pivoting angle of the ejectionlever 200. The ejection lever 200 has, in the same plane as its firstleg, a control boss consisting of two sliding bosses 202 which arearranged in a fork like manner which are guided in a guide channel 203narrowing in the stroke direction, until their ends pointing outward ina hook like manner come into engagement with the lower end of a guidetrack 205 when the first stroke is terminated. The guide track 205 risesin the direction of the longitudinal axis F in a ramp like manneropposite to the injection direction and is positioned and oriented insuch a way that, when the control sleeve 6 is rotated into its openingand securing position P2 and the slide 2 is consequently moved back intoits locking position A1, the two sliding bosses pass onto this guidetrack 205 and the ejection lever 200 is therefore guided upward, so thatthe ejection movement is concluded when the control sleeve 6 has reachedits opening and securing position P2.

As another additional means, the injection device has a signal meanswhich is actuated at the end of the second stroke H2 after injection hastaken place. There is provision, in this case, for this signal means toconsist solely of mechanically acting structural elements and, by meansof a bell 306, to emit an acoustic signal, in order to generate whichthere is a striking pin 305 which is movable transversely to thelongitudinal axis F and which loads the edge region of the bell 306 in apulse like manner.

The detailed design of the signal means is illustrated especially inFIGS. 3, 4 and 5:

One end of a tension rod 300 is held movably in a bore of the tappet 4,the other end of said tension rod engaging on a collar like yoke 302held on the holding block 31 which is fastened in the rearside 74 of thehousing and which serves, on its front side, as an abutment for thehelical spring 3. The bell 306 is also held on this basic body 31 bymeans of a circumferential groove, so that said bell covers the yoke302. The axis of rotation 303 of the yoke 302 runs, in this case,through the longitudinal axis F perpendicularly to the drawing plane ofFIG. 3. At its end facing away from the tension rod 300, the yoke 302engages over an edge groove of the striking pin 305 which is fixed inthe locking position by a tongue 308 of the tappet 4. The striking pin305 is held forcibly in the drawing plane of FIG. 3 by means of twosprings 304 and 307. The tension rod 300 is surrounded by a compressionspring 309 which ensures that the yoke 302 remains in the catch positionillustrated in FIG. 3

The length of the tension rod 300 is selected in such a way that, at theend of injection (FIG. 10), the tappet 4,via an abutment 301, loads thetension rod 300, so that the latter, in turn, pivots the yoke 302,whereupon the opposite end of the yoke 302 releases the circumferentialcatch of the striking pin 305, so that, under the coordinated force ofthe two springs 304, 307, the striking pin 305 (already released by thetongue 308) is thrown against the inner edge region of the bell 306, asillustrated in FIG. 10. The spring constants of the springs 304 and 307are, in this case, dimensioned in such a way as first to ensure that thestriking pin 305 reaches the bell 306 in order to trigger the acousticsignal, but the spring 307 then draws the striking pin 305 back again,so that the bell can vibrate freely, without damping effects caused bythe striking pin 305 resting on it, and can generate the typical soundof a clapper-actuated bell. When the tappet 4 returns to its lockingposition, the sloping end of the tongue 308 slides onto the tip of thestriking pin 305 again and presses the latter back until the detent pawlof the yoke 302, then loaded again by the compression spring 309,engages over the edge groove of the striking pin 305 and secures thelatter.

Now that the structural preconditions have been presented in detail,their functioning will also be described briefly, step by step, withreference to a complete injection operation:

The position and arrangement of the structural parts, as illustrated inFIGS. 1 to 3, is selected as the starting position:

Here, the control sleeve 6 is in its opening and securing position P2,that is to say a syringe 1 can be inserted through the loading orificesL6 and L7 into the position provided for it in the slide 2. At the sametime, the control sleeve 6 is held in the opening and securing positionP2 by the catch element 77 penetrating into the recess 77A.

The two lifting bolts 42, 43 are in their position B (FIG. 12) or in theuppermost position 42 c, 43 c, illustrated in FIG. 13, on theirassociated control cam portions.

The tappet 4 and slide 2 are in their rear locking position A1 and A2,since the securing pawls 41 are in engagement with the two control pawls53 and 54 and activation of the trigger means is not possible, since thenose 5A of the actuating button is blocked by the edge region of thecylindrical control portion 6A of the control sleeve 6.

The tongue 308 on the guide portion 4A of the tappet 9 has its rear endface in contact with the conical striking pin 305, and the detent pawlof the yoke 302 is pressed by the force of the spring 309 over theperipheral edge of the striking pin 305 and retains the latter. Theactivation of the bell 306 is therefore likewise not possible in thisposition. The spring 3 is in its compressed, that is to say ready-to-actstate.

When the syringe 1 is inserted with its protective cap 11 into the slide2 and is fixed by means of its syringe collar 12, the control sleeve 6is rotated through 180° with one hand by the user, the user's other handretaining the handling portion 7A of the housing 7. The loading orificeL7 of the housing 7 is thereby closed by the control sleeve 6 and theclosing and operating position P1, illustrated in FIG. 9, of the controlsleeve 6 is consequently assumed. In this position, the contact element77 then penetrates into the depression 77B in the control sleeve 6 andthe lifting bolts 42, 43 are in position C (12) or position 42 d; 43 d(13). The recess 6A1 in the rear edge region of the cylindrical controlportion 6A simultaneously comes into the region of the nose 5A of theactuating button, so that the injection device can consequently be usedin the closing and operating position P1.

For this purpose, first the protective cap 11 is removed from the needle13 of the syringe 1 and the injection device is applied to the intendedplace of injection. After proper positioning, the trigger means is thenactivated, that is to say the actuating button 5 is pressed into thehousing 7, with the result that, after a short travel in the millimeterrange, the control pawls 53, 54 release the two securing pawls 41.

As soon as this has taken place, the spring 3 can exercise its effectand presses forward the tappet 4 and slide 2 still connectednonpositively to one another via the coupling element 8, that is to say,under the delaying effect of the rotation damper 100, the first strokeH1 is executed, causing the injection needle 13 to prick into thetissue. During this movement of the slide 2, the ejection lever 200,which is held in the slide 2 via the pin 201, moves with its slidingbosses 202 on the track 203. As a result of the narrowing track 203, thetwo legs 204 are pressed inward, so that, toward the end of the firststroke, tension is generated, by means of which the sliding bosses 202jump outward and come into engagement with the guide track 205.

Moreover, in the exemplary embodiment shown in FIGS. 13 and 14, at thestart of the first stroke H1, the lifting bolts 42, 43 loaded by thesprings 44, 45 slide over the sliding ramps 61, 62 into the free space63. As explained above, the end of the first stroke H1, which the slide2 and the tappet 4 execute jointly, is defined in that the couplingelement 8, when it slides along on the inner surface of the housing 7,finally reaches the catch element designed as a depression 72. By virtueof the transmission of force via the sloping surfaces of thedepressions, the coupling element 8 slides into the depression 72, withthe result that the positive connection and nonpositive connectionbetween the tappet 4 and slide 2 is canceled and the slide 2 has thenarrived in its front end position in the housing 7 and is fixedpositively. The injection needle 13, too, has consequently reached itsforemost position in the longitudinal axis F.

Under the action of the spring 3, then, the tappet 4 alone executes thesecond stroke H2, FIG. 6 illustrating directly the start of the secondstroke when the recess 81 in the tappet 4 moves away from the couplingelement 8 which is now held in the housing 7.

As the second stroke continues, the front side of the tappet 4 loads theplunger 14 of the syringe 1, presses said plunger into the syringe andthus causes the injection fluid to be injected; this position toward theend of the second stroke is illustrated in FIG. 7.

At the end of injection, that is to say when the tappet 4 has reachedits front end position, it actuates the tension rod 300 via the abutment301 (FIG. 10), as a result of which the catch of the striking pin 305 isreleased via the lever 302. Under the action of the spring 304, saidstriking pin butts onto the inner edge region of the bell 306, so thatthe sound initially mentioned, which is clearly detectable by theinstrument user, is generated. Under the counteraction of the spring307, the striking pin 305 is drawn back from the bell immediately afterthis action, so that the bell can vibrate freely.

The user, then, has obtained information on the termination of theinjection operation and can consequently lift off the injection devicefrom the place of injection and draw the injection needle 13 out of thetissue.

In order to extract the syringe 1, then, the control sleeve 6 is againmoved through 180° from its closing and operating position P1 into theopening and securing position P2 (FIG. 2), so that the syringe 1 becomesaccessible again. This rotation of the control sleeve 6 initially hasthe effect that, by means of the control cam portions 64 to 67, incooperation with the lifting bolts 42, 43, the rotational movementthrough 180° is converted into the counterstroke ΔH of the tappet 4(which precautions, not illustrated, prevent from executing a radialmovement). When the rear abutment 46 reaches the slide 2 again, thecoupling element 8 slides out of engagement with the housing 7 again andthe slide 2 is coupled to the movement of the tappet 4 again.

During this first portion of the return movement of the slide 2, thesliding bosses of the ejection lever 200 move, with the slide 2,obliquely upward on the guide track 205, so that, in this region, therotation of the control sleeve 6 is converted into a rotational movementof the ejection lever 200 which finally 10 engages under the syringe 1and lifts it up when the rotation of the control sleeve 6 has ended.

Toward the end of this rotational movement, the sloping ends of thesecuring pawls 41 slide on the corresponding slopes of the two controlpawls 53 and 54, until, at the end of this operation, the spring-loadedtrigger means catches again with its control pawls 53, 54 behind therear flanks of the two securing pawls 41, before the two lockingpositions A1 and A2 of the tappet 4 and slide 2 are then finally assumedagain.

Simultaneously with this operation, the tongue 308 also penetrates againthrough the associated orifice in the trigger means. By virtue of thecorrespondingly sloping contact surfaces between the tongue 308 andstriking pin 305, the axial movement of the tongue 308 is 30 convertedinto a corresponding transverse movement of the striking pin 305, untilthe latter finally again reaches a position where the tension rod, whichin the meantime has been pressure-loaded again by the compression spring309, can pivot the lever 302 in such a way that the opposite end of thelatter catches again on the circumferential edge of the striking pin305.

The syringe 1 can then be extracted and the injection device is stored,in this state, until its next use.

However, rotation of the control sleeve 6 is likewise possible, so thatthe operations as described above can also be carried out “idly”. At allevents, the rotation of the control sleeve 6 through 180° into itsopening and securing position P2 causes loading of the tappet 4 and ofthe slide 2 and the return of these into their locking position, so thatthe injection device is then ready for receiving a new syringe 1.

In order to illustrate the last-mentioned conversion of the rotationalmovement of the control sleeve 6 into the axial displacement of thetappet and slide back into their locking position, these sequences willbe explained once again with reference to FIGS. 11 and 14:

In the preferred exemplary embodiment (FIGS. 11 and 12), after injectionhas taken place, the two lifting bolts 42, 43 are in their lowermostposition D; upon rotation of the control sleeve 6 in the direction DR,the two lifting bolts slide in the direction of the obliquelyupward-oriented arrows to “their” portion 68, 69 of the control cam andin the process execute the counterstroke ΔH. On reaching the apex of thecontrol cam portions 68, 69 (position B) after a rotation aboutapproximately 180°, the locking positions of the tappet 4 and slide 2are again attained. Upon further rotation of the control sleeve 6, againby 180°, the lifting bolts then reach position C, in which the detentlocking is also effected by means of the detent element 77/recess 77A,and the change of syringes can be made. After reactivation of theinjection device, the two lifting bolts move (arrows S) over thevertical flank of their control cam portion 68, 69, after thetermination of the injection process, back to their position D.

In the second exemplary embodiment, having two control cams (FIGS. 13and 14), after injection has taken place, that is to say at the end ofthe two strokes H1 and H2, the first lifting bolt 42 is at the lowestpoint of its associated control cam 64 and, correspondingly, the secondlifting bolt 43 is at the lowest point of its associated control cam 65.When the control sleeve 6 is rotated in the direction of the arrow DR,then, the two lifting bolts 42, 43 slide relatively in the oppositedirection (small arrows directed obliquely upward) on the control cams64 and 65 and, at the same time, execute the counter stroke ΔH which isdirected opposite to the two strokes H1 and H2 when injection is beingcarried out. For each rotary angle unit of the control sleeve 6, thecontrol cam 64 or 65 runs relatively steeply, since, here too, thespring 3 is still largely in its detensioned position and thereforeopposes only a little force to the corresponding counter stroke of theslide 2 and tappet 4 during the rotation of the control sleeve 6. Theshape of the control cams 64 and 65 is therefore a direct mirror imageof the increasing force of the spring 3 counteracting the counterstrokeΔH, and optimization can be achieved insofar as, for each angle unit ofthe rotation of the control sleeve 6, an approximately equal torque hasto be exerted by the user, thus ensuring convenient handling. Thismeans, conversely, that rotation of the control sleeve 6 through a fixedrotary angle at the start of rotation leads to a greater correspondingcounterstroke than at the end of the rotational movement, where thevirtually full tension force of the spring 3 demands a very flat run ofthe control cam portions 66, 67.

By virtue of the offset of the intersection points of the control camportions 64, 67 and 65, 66, as a result of the force acting by means ofthe spring 44 on the first lifting bolt 42 the latter executes an axialmovement, during which, in the position 42, it leaves 15 its controlportion 64 and slides onto the control portion 67. At this moment oftransition, however, the second lifting bolt 43 is still located on itscontrol cam portion 65, so that the transmission of torque from thecontrol sleeve 6 to the tappet 4 remains guaranteed.

In the position 42 b, 43 b, after a rotation of the control sleeve 6 ofsomewhat less than 180°, the two lifting bolts 42, 43 have generated thenecessary counterstroke ΔH of the tappet 4, said counterstrokecorresponding in amount to the sum of the two strokes H1 and H2, asillustrated in FIG. 13, and the locking position of the tappet 4 and,consequently, the slide 2 is reached. The control sleeve is then rotatedsomewhat further, until, and only then, the already above mentionedcatching of the catch element 77 in the recess 77A is brought aboutagain, thereby also telling the user that locking is now ensured againand the empty syringe 1 can be extracted and, if appropriate, a new oneinserted again. The two lifting bolts 42, 43 assume the position 42 c,43 c.

At the transition of the control sleeve 6 from its opening and securingposition P2 into its closing and operating position P1, the two liftingbolts 42 and 43 are again guided through 180° into their originalangular position at 42 d and 43 d, but so as to be offset by the amountof the sum of the two strokes H1 and H2; only when the injection deviceis activated by the trigger means, now becoming possible again, do thetwo lifting bolts, via the sliding ramps 61, 62, again reach theposition, presupposed at the outset of the operating description, at thelower vertex of their associated control cam portions after injectionhas ended.

In FIGS. 16-19, an especially preferred embodiment of the slide is shownin cooperation with a gear. As a result of this concept of a “gearslide”, it becomes possible to adapt the second stroke H2, which ispredetermined in the above-described exemplary embodiment, in terms ofits value to the injection stroke of a special syringe, since not allsyringes used are standardized with regard to this value. By the choiceof a suitable gear, it is accordingly possible, on the basis of thestroke H2 of the tappet 4′, to generate a stroke H2′ that is shorterstep-down gear ratio) or longer (step-up gear ratio) than the stroke H2of the tappet 4′.

In the exemplary embodiment shown in FIGS. 16-19, a gear with a gearstep-up ratio is shown, that is, the injection stroke H2′ is longer thanthe stroke H2 of the tappet 4′. It should be especially noted here thatthe two strokes H2 and H2′ are in the same direction, for instance incontrast to versions (DE 28 12 729 A1), where although a gear version isalso claimed, the actuation stroke and injection stroke are orientedcontrary to one another.

The structural attainment of this embodiment concept will now bedescribed in further detail:

The slide 2′ is embodied in the manner of a tub and guides the tappet 4′on the one hand but on the other hand also guides a thrust rod 4″parallel to one another. The thrust rod 4″ has a first rack S1 on itsunderside, while a pressure plate 4″ is formed onto the front side andacts on the syringe plunger 14 of an injection syringe 1 which is heldin the syringe receptacle by its collar 12.

On its end located in front in the injection direction, the tappet 4′ inforklike fashion includes an arrangement of a total of three gearwheels, having a middle, first gear wheel Z1 which meshes with the rackS1 of the thrust rod 4″, and two gear wheels Z2A, Z2B of lesserdiameter, which are secured coaxially on both sides of this central,first gear wheel Z1 and mesh with a respective rack S2A and S2B on thebottom of the slide 2′.

The two racks S2A, S2B on the bottom of the tublike slide 2′ are spacedapart far enough that the gear ring of the first gear wheel Z1 canprotrude between these two racks.

In the preferred exemplary embodiment shown in FIGS. 6-19, the firstgear wheel Z1 thus consequently meshes with the rack S1 on the undersideof the thrust rod 4″, and the two laterally disposed second gear wheelsZ2A/Z2B each mesh with their respective associated second rack S2A/S2B.

In the exemplary embodiment shown in the drawings, what is involved isconsequently a gear step-up ratio; that is, the second stroke H2 of thetappet 4′ is converted into a stroke H2′ of the thrust rod 4″ that ismore than twice as long as the second stroke H2.

With this device, space is accordingly made in particular for injectionsyringes 1 that have a very long injection stroke and a correspondinglylong syringe plunger 14, as is shown particularly clearly in FIGS. 17.

The overall concept and the mode of operation of the slide 2′ as such ininteraction with the other components of the injection device is fillypreserved here, as clearly shown in FIGS. 18 and 19, where instead ofthe carriage 2 in the exemplary embodiments described above, the “gearslide” 2′ is built in. The only resultant change is that because of thecorresponding structural height, which is approximately equivalent tothe radius of the first gear wheel Z1, a corresponding deviation of theinjection axis from the longitudinal axis F of the housing is broughtabout, which can be taken into account by suitable simple predetermineddimensions on the housing.

Particularly from the isolated view of the “gear slide” 2′ in FIGS. 16and 17, it becomes clear that such a version is not limited to theinjection device as described in its details at the outset, but also canbe used or employed in injection devices of a conventional design, bymaking simple modification. For instance, in such a simple case, theslide 2′ can be connected in stationary fashion to a simple housing, andthe tappet 4′ can be provided, on its side remote from the injectiondirection, with an actuating end that protrudes out of this housing, sothat here the simplest case of a syringe actuation is made possible,with the desired step-up of the actuating stroke to an injection strokeoriented in the same direction.

What is claimed is:
 1. An injection device for actuating a syringe, in particular a disposable syringe, with drive and control means which are held in a housing and which cause the injection operation to take place successively in such a way that first a linear displacement of the syringe (1) with the injection needle takes place for introducing the injection needle into the skin, and then the injection of the injection fluid takes place, and the drive and control means contain a control sleeve (6) which is displaceable between a closing and operating position (P1), which prevents access to the syringe (1) and releases a trigger means for the injection operation, and an opening and securing position (P2), which allows the syringe (1) to be inserted and extracted, characterized in that the control sleeve (6), over part of its circumference, has a loading orifice (L6) for inserting and extracting the syringe (1), and that it is rotatable between the closing and operating position (P1) and the opening and securing position (P2) by a control angle (a) on the casing surface (M) of the housing (7).
 2. The injection device as claimed in claim 1, characterized in that the control sleeve (6) has a substantially cylindrical middle portion (6B), which has the loading orifice (L6).
 3. The injection device as claimed in claim 1, characterized in that the housing (7) has an essentially cylindrical middle portion (7B) which has, over part of its circumference, a loading orifice (L7) for inserting and extracting the syringe (1).
 4. The injection device as claimed in claim 2 characterized in that the housing (7) has an essentially cylindrical middle portion (7B) which has, over part of its circumference, a loading orifice (L7) for inserting and extracting the syringe (1) and in that the two loading orifices (L6, L7) extend over part of the respective circumference of their associated structural part (6, 7), the circumferential angle (α1, α2) of which is greater than 180°, so that, in the closing and operating position (P1), the syringe (1) is surrounded completely by the housing (7) and the control sleeve (6) and, when the control sleeve (6) is in the opening and securing position (P2) rotated through the control angle (α) the two loading orifices (L6, L7) are at least partially congruent.
 5. The injection device as claimed in claim 1, wherein a first stroke (H1) of a slide (2), in which the syringe (1) is held for introducing the injection needle (13) is provided, within the housing (7), between a locking position (A1) and an advanced position (V1).
 6. The injection device as claimed in claim 5, characterized in that a second stroke (H2) of a tappet (4) in the operational axis (F) relative to the slide (2) for injecting the injection fluid is provided, within the housing (7), between a locking position (A2) and an advanced position (V2).
 7. The injection device as claimed in claim 6, characterized in that the relative positions of the tappet (4) and slide (2) are defined by a coupling element (8), in such a way that, after the trigger means has been actuated, the second stroke (H2) of the tappet (4) directly follows the first stroke (H1) of the slide (2) and the two strokes (H1, H2) are added together.
 8. The injection device as claimed in claim 7, characterized in that, during the first stroke (H1) of the slide (2), the coupling element (8) couples the latter and the tappet (4) to one another via a first catch element (81) in the tappet (4) and, after the first stroke (H1), releases the coupling by means of a second catch element (72) in the housing (7), so that the tappet (4) alone then carries out the second stroke (H2).
 9. The injection device as claimed in claim 1, characterized in that the control sleeve (6), housing (7), slide (2) and tappet (4) are designed at least in portions, as cylindrical or hollow-cylindrical portions lying coaxially to one another.
 10. The injection device as claimed in claim 9, characterized in that the housing (7) has, in a rear cylindrical handling portion (7A), an annular groove (75), in which a cylindrical control portion (6A) of the control sleeve (6) is guided rotatably.
 11. The injection device as claimed in claim 10, characterized in that the control sleeve (6) has a front tapered guide portion (6C) which is held rotatably on the housing (7).
 12. The injection device as claimed in claim 1, characterized in that the closing position (P1) and the opening position (P2) are secured by a catch element (77) acting between the housing (7) and control sleeve (6) and by depressions (77A, 77B) in the housing (7) which act in a manner offset relative to one another by the control angle (α).
 13. The injection device as claimed in claim 9, characterized in that the slide (2) is designed, over a first portion (2A) guided in the housing (7), as a hollow cylinder in which the tappet (4) is centrally mounted axially displaceably.
 14. The injection device as claimed in claim 13, characterized in that the slide (2) has a U-shaped cross section in a second portion (2B) guided in the housing 10 (7), and a groove-shaped or slit like retention (21) for positioning the syringe collar (12) held in this retention (21) in such a way that the end face of the syringe plunger can be displaced in the injection direction by the tappet (4).
 15. The injection device as claimed in claim 9, characterized in that the tappet (4) has, at it send pointing toward the handling portion (7A) of the housing (7), a guide portion (4A) which is guided in the 20 housing (7) and which has the same outside diameter as the first portion (2A) of the slide (2).
 16. The injection device as claimed in claim 15, characterized in that a joint drive means for generating the two strokes (H1, H2) by the slide (2) and the tappet (4) is accommodated between the rear end face of the guide portion (4A) of the tappet (4) and the housing rear wall (74).
 17. The injection device as claimed in claim 16, characterized in that the drive means is a helical spring (3) arranged coaxially to the longitudinal axis (F).
 18. The injection device as claimed in claim 15, wherein a first stroke (H1) of a slide (2), in which the syringe (1) is held for introducing the injection needle (13) is provided, within the housing (7), between a locking position (A1) and an advanced position (V1), and characterized in that a second stroke (H2) of a tappet (4) in the operational axis (F) relative to the slide (2) for injecting the injection fluid is provided, within the housing (7), between a locking position (A2) and an advanced position (V2), and in that there is integrally formed on the rear side of the guide portion (4A) of the tappet (4) at least on securing pawl (41) which, in the opening and securing position (P2), is in releasable engagement with at least one control pawl (53, 54) of the trigger means, said control pawl being displaceable transversely to the longitudinal axis (F), and which holds the tappet (4) in its locking position (A1) counter to the pretension of the helical spring (3).
 19. The injection device as claimed in claim 18, characterized in that the trigger means is guided outward through the housing (7) and there forms an actuating button (5) for releasing the securing pawl (41) and, consequently, the two strokes (H1, H2).
 20. The injection device as claimed in claim 19, characterized in that the displacement of the actuating button (5) is possible only when the control sleeve (6) is in the closing and operating position (P1).
 21. The injection device as claimed in claim 20, characterized in that the cylindrical control portion (6A) of the control sleeve (6) has an edge recess (6A1), through which a nose (5A) of the actuating button (5) can pass in the closing and operating position (P1).
 22. The injection device as claimed in claim 15, characterized in that control elements are held in the guide portion (4A) of the tappet (4), said control elements cooperating with profiles which form at least one control cam are formed on the inner casing surface (MI) of the cylindrical control portion (6A) of the control sleeve (6) and which act as control cams (64, 66; 65, 67).
 23. The injection device as claimed in claim 22, characterized in that in the control elements consist of at least one lifting bolt (42,43) which loads the control cam portions (64, 67; 65, 66; 68, 69) in such a way that, as a result of rotation of the control sleeve (6) from the closing and operating position (P1), after the execution of the two strokes (H1, H2), through the functional angle into the opening and securing position (P2), the torque applied at the same time is converted via the control cam portions (64, 67; 65, 66; 68, 69) into a linear restoring force counter to the tension force of the helical spring (3), with the result that the tappet (4) and the slide (2) execute a counterstroke (OH) in the housing (7) until in their locking positions (A1, A2), the securing pawls (41) of the tappet (4) come into engagement with the control pawls(53, 54) of the trigger means (5) again.
 24. The injection device as claimed in claim 23, characterized in that two lifting bolts (42, 43) of different thickness spring-loaded in the direction of the casing surface (MI) are provided, which are guided by two control cams (64, 67 and 65, 66) arranged so as to be offset vertically in the inner casing surface (MI) in such a way that, in each axial position of the tappet (4), the conversion of the torque of the control sleeve (6) takes place via at least one of the lifting bolts (42, 43).
 25. The injection device as claimed in claim 1, characterized in that the control sleeve (6), when in the closing and operating position (P1), allows a view of the syringe (1).
 26. The injection device as claimed in claim 25, characterized in that the control sleeve (6) is made at least partially from transparent plastic.
 27. The injection device as claimed in claim 1, characterized in that at least some of the essential structural operating parts (2, 4, 6, 7) are formed from plastic.
 28. The injection device as claimed in claim 6, characterized in that the acceleration of the slide (2) into its advanced position (V1) during the first stroke (H1) is limited by a rotation damper (100) which is connected to the housing (7) via a rack (101).
 29. The injection device as claimed in claim 23, characterized in that the housing (7) has an essentially cylindrical middle portion (7B) which has, over part of its circumference, a loading orifice (L7) for inserting and extracting the syringe (1), and in that there is provided opposite the loading orifice (L7) of the housing (7) an ejection means which, after injection has taken place, lifts the syringe (1) in the direction of the loading orifices (L6, L7) during the opening of the loading orifice (L7) as a result of the rotation of the control sleeve (6) into the opening and securing position (P2).
 30. The injection device as claimed in claim 29, characterized in that the ejection means contains an ejection lever (200), one end of which is held pivotably on the slide (2) by means of a pin (201), in such a way that its other end can be moved in the direction of the syringe (1).
 31. The injection device as claimed in claim 30, characterized in that, in order to control the movement of the ejection lever (200), the latter has a control boss which, at the end of the first stroke (H1), comes into engagement with a guide track (205) which rises in the direction of the operating axis (F) in a ramplike manner opposite to the injection direction, so that the lifting of the ejection lever (200) takes place during the rotation of the control sleeve (6) into the opening and securing position (P2).
 32. The injection device as claimed in claim 31, characterized in that the control boss consists of two sliding bosses (202) which are arranged in a forklike manner on the ejection lever (200) and which are guided in a guide channel (203) narrowing in the stroke direction, until their ends pointing outward in a hooklike manner come into engagement with the lower end of the guide track (205).
 33. The injection device as claimed in claim 1, characterized in that a signal means is provided, which is actuated at the end of the second stroke (H2) after injection has taken place.
 34. The injection device as claimed in claim 33, characterized in that the signal means consists solely of mechanically acting structural elements.
 35. The injection device as claimed in claim 33, characterized in that the signal means generates an acoustic signal.
 36. The injection device as claimed in claim 34, characterized in that the signal means generates an acoustic signal and in that the signal is generated by means of a bell (306), the edge region of which is loaded by means of a striking pin (305) in order to generate the signal.
 37. The injection device as claimed in claim 36, characterized in that the striking pin (305) is actuated, via a lever arrangement (302), by a tension rod (300) displaceable parallel to the operating axis (F) by the slide (2) and loaded by a spring (309).
 38. The injection device as claimed in claim 37, characterized in that the striking pin (305) is secured by means of springs (304, 307) and is loaded in such a way that the bell (306) receives only a short pulse for generating the signal.
 39. The injection device of claim 6, characterized in that the tappet (4′) is coupled via a linear gear to a thrust rod (4″), which actuates the syringe plunger (14).
 40. The injection device of claim 39, characterized in that the ratio of the gear is selected such that the second stroke (H2) of the tappet (4′) is converted into a stroke in the same direction of the thrust rod (4″), which corresponds to the injection stroke of the syringe plunger (14).
 41. The injection device of claim 40, characterized in that the thrust rod (4″) is guided parallel to the tappet (4′) by the slide (2′).
 42. The injection device of claim 41, characterized in that the front portion of the tappet (4′), at least two gear wheels (Z1, Z2) of different diameter are coaxially secured to one another, of which the first gear wheel (Z1) meshes with a first rack (S1) on the thrust rod (4″), and the second gear wheel (Z2) meshes with a second rack (S2) on the slide (2′).
 43. The injection device of claim 40, characterized in that the front portion of the tappet (4′), at least two gear wheels (Z1, Z2) of different diameter are coaxially secured to one another, of which the first gear wheel (Z1) meshes with a first rack (S1) on the thrust rod (4″), and the second gear wheel (Z2) meshes with a second rack (S2) on the slide (2′) and in that the diameter of the two gear wheels (Z1, Z2) specifies the ratio of the gear (Z1, Z2; S1, S2).
 44. The injection device of claim 43, characterized in that the front portion of the tappet (4′) fits in forklike fashion over an arrangement of three gear wheels (Z2A, Z1, Z2B), of which the middle, first gear wheel (Z1) has the larger diameter, and the two outer, second gear wheels (Z2A, Z2B) mesh with two second racks (S2A, S2B).
 45. The injection device of claim 42, characterized in that the first rack (S1) is an integral part of the thrust rod (4″).
 46. The injection device of claim 42, characterized in that the second rack or racks (S2; S2A, S2B) are an integral part of the slide (2′).
 47. The injection device of claim 39, characterized in that the longitudinal axis of the syringe (1) is located parallel to the longitudinal axis (F) of the housing (7).
 48. The injection device of claim 41, characterized in that in the front portion of the tappet, a gear wheel is supported which meshes with a first rack on the thrust rod and with a second rack on the injection stroke is twice as long as the stroke of the tappet. 